do all (most?) epoxies bond to each other?

do all (most?) epoxies bond to each other?

Post by mx » Thu, 10 Dec 2009 00:03:56


Will all epoxies bond to one another?  I have some West GFlex, which I
want to use thickened to fill a gap between two loosely-fit fiberglass
parts, and some System Three laminating resin (Clear Coat, I think, I
don't have it with me right now) that I then want to use with glass
tape to reinforce over the surface of the joint.  Will the epoxies
bond well to each other, if the glass is applied within a few days of
the first resin?

Also, is colloidal silica and microballons the same?  I have an old
bag of house-brand microballons from Fiberlay, and colloidal silica is
recommended as a thickener.   I feel like I used to know the answer to
this...but, apparently, I'm an idiot!

Thanks,
Mike

 
 
 

do all (most?) epoxies bond to each other?

Post by max camiran » Thu, 10 Dec 2009 05:18:17


Quote:
> Will all epoxies bond to one another? ?I have some West GFlex, which I
> want to use thickened to fill a gap between two loosely-fit fiberglass
> parts, and some System Three laminating resin (Clear Coat, I think, I
> don't have it with me right now) that I then want to use with glass
> tape to reinforce over the surface of the joint. ?Will the epoxies
> bond well to each other, if the glass is applied within a few days of
> the first resin?

> Also, is colloidal silica and microballons the same? ?I have an old
> bag of house-brand microballons from Fiberlay, and colloidal silica is
> recommended as a thickener. ? I feel like I used to know the answer to
> this...but, apparently, I'm an idiot!

> Thanks,
> Mike

Colloidal silica and microballoons aren't the same thing. Colloidal
silica will be harder to sand when cured. Microballoons are a lighter
filler.

As long as you give the first application of epoxy a wipe and a bit of
a sanding before you lay on the glass tape, it will bond.

-m

 
 
 

do all (most?) epoxies bond to each other?

Post by mx » Thu, 10 Dec 2009 05:25:11


Quote:

> > Thanks,
> > Mike

> Colloidal silica and microballoons aren't the same thing. Colloidal
> silica will be harder to sand when cured. Microballoons are a lighter
> filler.

presumably microballons are hollow, so the fillet is weaker with them?
Quote:

> As long as you give the first application of epoxy a wipe and a bit of
> a sanding before you lay on the glass tape, it will bond.

It's chilly here this week (Seattle) and my little garage heater is
overmatched, so after 24 hours, the first pour will probably be just
hard enough to remove the clamps, so still pretty green.  I can
probably give it a solvent wipe, but not sure about sanding at that
stage.

 
 
 

do all (most?) epoxies bond to each other?

Post by Lew Hodget » Thu, 10 Dec 2009 05:28:42

Quote:

> Will all epoxies bond to one another?

There are two (2) types of bonding, chemical and mechanical.

Chemical bonding occurs when a follow up layer of resin is applied
over an epoxy surface that has not totally cured.

Mechanical bonding occurs when a layer of epoxy is applied over a
totally cured epoxy surface.

You appear to be describing old work, thus mechanical bonding will
apply.

A small right angle sander with 24 grit discs will be your friend for
this job.

BTDT, forget the T-Shirt.

Good luck.

BTW, micro-balloons as a filler will do the job, especially when you
lay a piece of glass tape over it.

Lew

 
 
 

do all (most?) epoxies bond to each other?

Post by mx » Thu, 10 Dec 2009 06:51:47


Quote:

> > Will all epoxies bond to one another?

> There are two (2) types of bonding, chemical and mechanical.

> Chemical bonding occurs when a follow up layer of resin is applied
> over an epoxy surface that has not totally cured.

> Mechanical bonding occurs when a layer of epoxy is applied over a
> totally cured epoxy surface.

> You appear to be describing old work, thus mechanical bonding will
> apply.

The premade glass parts are old (one is "new" but was made at least 6
months ago).  Their surfaces to be bonded are fairly rough, so should
give a half-way decent mechanical bond.  The glass tape is to insure
that the load is carried out over a large area of the old hull, since
its layup is not terribly thick.

But since I'm considering using 2 different epoxies for the fillet and
new cloth reinforcement, i was uncertain if they might be incompatible
in forming chemical bonds between the two new layers, or if it could
be assumed that any two common epoxies would stick to each other
chemically if the first layer is only partially cured.

Thanks,
Mike

 
 
 

do all (most?) epoxies bond to each other?

Post by Lew Hodget » Thu, 10 Dec 2009 06:58:58


------------------------------------------
The premade glass parts are old (one is "new" but was made at least 6
months ago).  Their surfaces to be bonded are fairly rough, so should
give a half-way decent mechanical bond.  The glass tape is to insure
that the load is carried out over a large area of the old hull, since
its layup is not terribly thick.

But since I'm considering using 2 different epoxies for the fillet and
new cloth reinforcement, i was uncertain if they might be incompatible
in forming chemical bonds between the two new layers, or if it could
be assumed that any two common epoxies would stick to each other
chemically if the first layer is only partially cured.

---------------------------------------

Assume you get only a mechanical bond and get on with it.

SFWIW, a right angle sander with 24 grit discs is your best friend if
you are going to work with glass.

Best $100 you will ever spend, IMHO.

Lew

 
 
 

do all (most?) epoxies bond to each other?

Post by matt_coli » Thu, 10 Dec 2009 07:21:55

Quote:

> Will all epoxies bond to one another?  I have some West GFlex, which I
> want to use thickened to fill a gap between two loosely-fit fiberglass
> parts, and some System Three laminating resin (Clear Coat, I think, I
> don't have it with me right now) that I then want to use with glass
> tape to reinforce over the surface of the joint.  Will the epoxies
> bond well to each other, if the glass is applied within a few days of
> the first resin?

> Also, is colloidal silica and microballons the same?  I have an old
> bag of house-brand microballons from Fiberlay, and colloidal silica is
> recommended as a thickener.   I feel like I used to know the answer to
> this...but, apparently, I'm an idiot!

> Thanks,
> Mike

You have gotten good answers, but one thing was not covered.
Most Epoxies blush to some extent.
If you don't sand both parts, then at least wash them well.  You can
actually use a detergent and clean water rinse.
Matt Colie
 
 
 

do all (most?) epoxies bond to each other?

Post by Bruce In Bangko » Thu, 10 Dec 2009 23:01:06

Quote:



>> > Will all epoxies bond to one another?

>> There are two (2) types of bonding, chemical and mechanical.

>> Chemical bonding occurs when a follow up layer of resin is applied
>> over an epoxy surface that has not totally cured.

>> Mechanical bonding occurs when a layer of epoxy is applied over a
>> totally cured epoxy surface.

>> You appear to be describing old work, thus mechanical bonding will
>> apply.

>The premade glass parts are old (one is "new" but was made at least 6
>months ago).  Their surfaces to be bonded are fairly rough, so should
>give a half-way decent mechanical bond.  The glass tape is to insure
>that the load is carried out over a large area of the old hull, since
>its layup is not terribly thick.

>But since I'm considering using 2 different epoxies for the fillet and
>new cloth reinforcement, i was uncertain if they might be incompatible
>in forming chemical bonds between the two new layers, or if it could
>be assumed that any two common epoxies would stick to each other
>chemically if the first layer is only partially cured.

>Thanks,
>Mike

Essentially "epoxy" is the same stuff, no matter where it comes from.
Certainly various sellers modify their product for some specific
purpose but basically they are all epoxy. So they will stick to each
other. Sand the old layer with a coarse sanding disk, wipe with
acetone and have at it.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

 
 
 

do all (most?) epoxies bond to each other?

Post by Bob La Lond » Thu, 10 Dec 2009 23:37:38


Quote:
> Will all epoxies bond to one another?  I have some West GFlex, which I
> want to use thickened to fill a gap between two loosely-fit fiberglass
> parts, and some System Three laminating resin (Clear Coat, I think, I
> don't have it with me right now) that I then want to use with glass
> tape to reinforce over the surface of the joint.  Will the epoxies
> bond well to each other, if the glass is applied within a few days of
> the first resin?

> Also, is colloidal silica and microballons the same?  I have an old
> bag of house-brand microballons from Fiberlay, and colloidal silica is
> recommended as a thickener.   I feel like I used to know the answer to
> this...but, apparently, I'm an idiot!

There are not many things epoxy doesn't stick to.
 
 
 

do all (most?) epoxies bond to each other?

Post by cavelam » Thu, 10 Dec 2009 23:41:35

Quote:



>> Will all epoxies bond to one another?  I have some West GFlex, which I
>> want to use thickened to fill a gap between two loosely-fit fiberglass
>> parts, and some System Three laminating resin (Clear Coat, I think, I
>> don't have it with me right now) that I then want to use with glass
>> tape to reinforce over the surface of the joint.  Will the epoxies
>> bond well to each other, if the glass is applied within a few days of
>> the first resin?

>> Also, is colloidal silica and microballons the same?  I have an old
>> bag of house-brand microballons from Fiberlay, and colloidal silica is
>> recommended as a thickener.   I feel like I used to know the answer to
>> this...but, apparently, I'm an idiot!

> There are not many things epoxy doesn't stick to.

Most poly-type plastics, duct tape, waxed paper, Elmer's glue, White Rain Hair
spray (PVA), etc.

Things I often use as mold release agents.

 
 
 

do all (most?) epoxies bond to each other?

Post by Bob La Lond » Fri, 11 Dec 2009 00:09:34


Quote:



>>> Will all epoxies bond to one another?  I have some West GFlex, which I
>>> want to use thickened to fill a gap between two loosely-fit fiberglass
>>> parts, and some System Three laminating resin (Clear Coat, I think, I
>>> don't have it with me right now) that I then want to use with glass
>>> tape to reinforce over the surface of the joint.  Will the epoxies
>>> bond well to each other, if the glass is applied within a few days of
>>> the first resin?

>>> Also, is colloidal silica and microballons the same?  I have an old
>>> bag of house-brand microballons from Fiberlay, and colloidal silica is
>>> recommended as a thickener.   I feel like I used to know the answer to
>>> this...but, apparently, I'm an idiot!

>> There are not many things epoxy doesn't stick to.

> Most poly-type plastics, duct tape, waxed paper, Elmer's glue, White Rain
> Hair spray (PVA), etc.

> Things I often use as mold release agents.

I'll have to remember that hair spray one.
 
 
 

do all (most?) epoxies bond to each other?

Post by Paul Oma » Fri, 11 Dec 2009 00:53:07

Quote:

> Will all epoxies bond to one another?  I have some West GFlex, which I
> want to use thickened to fill a gap between two loosely-fit fiberglass
> parts, and some System Three laminating resin (Clear Coat, I think, I
> don't have it with me right now) that I then want to use with glass
> tape to reinforce over the surface of the joint.  Will the epoxies
> bond well to each other, if the glass is applied within a few days of
> the first resin?

> Also, is colloidal silica and microballons the same?  I have an old
> bag of house-brand microballons from Fiberlay, and colloidal silica is
> recommended as a thickener.   I feel like I used to know the answer to
> this...but, apparently, I'm an idiot!

> Thanks,
> Mike

epoxies are a universal primer and epoxy will stick to epoxy, but watch
out for amine blush. Some/most venders (like the ones you mention)
sell the bushing epoxies because they make more profit/ Blush can affect
the bond between layers.

fumed silica is a common thickener... microspheres are tiny hollow
spheres, very light and fine (comes in different densities) - thickens
the epoxy but acts like tiny ball bearings in the epoxy

paul oman - progressive epoxy polymers inc.   www.epoxyproducts.com and
www.epoxyusa.com

--

 
 
 

do all (most?) epoxies bond to each other?

Post by I am Tos » Fri, 11 Dec 2009 01:06:26



Quote:


> > Will all epoxies bond to one another?  I have some West GFlex, which I
> > want to use thickened to fill a gap between two loosely-fit fiberglass
> > parts, and some System Three laminating resin (Clear Coat, I think, I
> > don't have it with me right now) that I then want to use with glass
> > tape to reinforce over the surface of the joint.  Will the epoxies
> > bond well to each other, if the glass is applied within a few days of
> > the first resin?

> > Also, is colloidal silica and microballons the same?  I have an old
> > bag of house-brand microballons from Fiberlay, and colloidal silica is
> > recommended as a thickener.   I feel like I used to know the answer to
> > this...but, apparently, I'm an idiot!

> > Thanks,
> > Mike

> epoxies are a universal primer and epoxy will stick to epoxy, but watch
> out for amine blush. Some/most venders (like the ones you mention)
> sell the bushing epoxies because they make more profit/ Blush can affect
> the bond between layers.

> fumed silica is a common thickener... microspheres are tiny hollow
> spheres, very light and fine (comes in different densities) - thickens
> the epoxy but acts like tiny ball bearings in the epoxy

> paul oman - progressive epoxy polymers inc.   www.epoxyproducts.com and
> www.epoxyusa.com

Has anyone mentioned that Balloons are more for filling and fairing,
Silica is more for structural work?

SmallBoats.com

 
 
 

do all (most?) epoxies bond to each other?

Post by Bob La Lond » Fri, 11 Dec 2009 01:14:01


Quote:




>>> Will all epoxies bond to one another?  I have some West GFlex, which I
>>> want to use thickened to fill a gap between two loosely-fit fiberglass
>>> parts, and some System Three laminating resin (Clear Coat, I think, I
>>> don't have it with me right now) that I then want to use with glass
>>> tape to reinforce over the surface of the joint.  Will the epoxies
>>> bond well to each other, if the glass is applied within a few days of
>>> the first resin?

>>> Also, is colloidal silica and microballons the same?  I have an old
>>> bag of house-brand microballons from Fiberlay, and colloidal silica is
>>> recommended as a thickener.   I feel like I used to know the answer to
>>> this...but, apparently, I'm an idiot!

>>There are not many things epoxy doesn't stick to.

> And some things it doesn't really stick to at all. I have plastic
> containers I've been mixing small batches of epoxy in for years. I let
> the remaining epoxy in them cure comepletely and then hold the
> container upside down over a wastebasket and flex it. All of the epoxy
> pops right out, leaving a completely clean-as-new container.

I need some of those.  I have been using plastic jars left over from other
things, and I just wind up throwing them away with each project.  Been
thinking about getting some big bags of plastic beer cups for it since they
are so cheap.
 
 
 

do all (most?) epoxies bond to each other?

Post by I am Tos » Fri, 11 Dec 2009 01:45:43


says...

Quote:







> >>> Will all epoxies bond to one another?  I have some West GFlex, which I
> >>> want to use thickened to fill a gap between two loosely-fit fiberglass
> >>> parts, and some System Three laminating resin (Clear Coat, I think, I
> >>> don't have it with me right now) that I then want to use with glass
> >>> tape to reinforce over the surface of the joint.  Will the epoxies
> >>> bond well to each other, if the glass is applied within a few days of
> >>> the first resin?

> >>> Also, is colloidal silica and microballons the same?  I have an old
> >>> bag of house-brand microballons from Fiberlay, and colloidal silica is
> >>> recommended as a thickener.   I feel like I used to know the answer to
> >>> this...but, apparently, I'm an idiot!

> >>There are not many things epoxy doesn't stick to.

> > And some things it doesn't really stick to at all. I have plastic
> > containers I've been mixing small batches of epoxy in for years. I let
> > the remaining epoxy in them cure comepletely and then hold the
> > container upside down over a wastebasket and flex it. All of the epoxy
> > pops right out, leaving a completely clean-as-new container.

> I need some of those.  I have been using plastic jars left over from other
> things, and I just wind up throwing them away with each project.  Been
> thinking about getting some big bags of plastic beer cups for it since they
> are so cheap.

I used to use the graduated 1 quart containers generally sold in the
paint section of Home Depot or such. Later I found them at a small resin
distributor for about .23 a piece. Use them a dozen or so times until
they crack or get too scratched up and toss 'em. easier to pour into
than beer cups, wider, and easier to work and stir in, a paint stirrer
works great...